Securing segment for the vibration damping of turbine blades and rotor device

ABSTRACT

A retaining segment for axially securing at least one rotor blade on a disk wheel of a rotor device of a jet engine is operatively connectable to at least one rotor blade and to a disk wheel. In a first peripheral area of the retaining segment that is laterally disposed in the circumferential direction in the installed state, a projecting region is provided, and in a second lateral peripheral area facing away from the first peripheral area, a receiving region is provided. The projecting region at least partially overlaps a receiving region of a retaining segment that is identical in design and arranged adjacently in the circumferential direction, and for performing frictional work with the receiving region. A rotor device has rotor blades arranged via blade roots substantially in the axial direction inside recesses of a disk wheel and secured by several such retaining segments.

This invention relates to a locking segment for axially securing at least one rotor blade on a disk wheel of a rotor device of a jet engine in accordance with the type defined in more detail in patent Claim 1 and to a rotor device in accordance with the type defined in more detail in patent Claim 12.

Rotor devices of jet engines known from actual practice have disk wheels and rotor blades connected thereto, which are arranged with blade roots in locating rails of the disk wheel running in the axial direction inside the disk wheel and which are secured on either one side or both sides with locking rings formed from locking segments and extending in the circumferential direction of the disk wheel to counter against any unwanted loosening from the disk wheel in the axial direction. The locking segments are each arranged next to one another in the circumferential direction of the rotor devices and are each in contact with one another at their lateral end faces.

The blade roots are designed in cross-section in at least some areas at least approximately fir tree-shaped or dovetail-shaped, with the fir tree-shaped or dovetail-shaped areas of the rotor blades being arranged in the locating rails of the disk wheel designed correspondingly thereto. A platform and an airfoil adjoin each of the blade roots of the rotor blades, said platforms each being designed wider than the blade roots between a blade root and an airfoil of a rotor blade in the circumferential direction of the disk wheel.

In order to reduce oscillations or vibrations occurring in the rotor blades during operation of a jet engine, it is known to place, between platforms of two rotor blades arranged adjacently to one another in respect of the airfoils of the rotor blades, and in each case underneath a joint area of the rotor blades, a damping element designed with a roof-shaped cross-section, extending in the axial direction of the disk wheel over a certain length underneath the joint areas between the platforms, contacting the rotor blades in the area of the platforms and also referred to as a damper underneath the platform.

The damping of the damping elements results from frictional forces in the contact area between the damping elements and the platforms of the rotor blades. Here, the damping effect of the damping elements is all the higher with a larger quotient from a distance (perpendicular in the radial direction of the disk wheel) between a damping element and a blade root end and the entire length of a rotor blade. This results from the fact that with increasing length of the blade roots, oscillation movements of the rotor blades at the position of the damping element increase and hence the frictional forces generated by the damping elements and counteracting the oscillations of the rotor blades increase, and that more kinetic energy from blade oscillations is absorbed and hence oscillation amplitudes of the airfoil are reduced.

It is known that there is sufficient damping when the blade roots are designed with a corresponding length and when the ratio described above is greater than a limit value known from actual practice.

It is disadvantageous that rotor blades with blade roots designed in this way each have an undesirably large mass, which at high speeds of the rotor device cause high stresses in the disk wheel in particular, which is why maximum permissible speeds of the rotor areas of such jet engines have to be limited to ensure a required service life. Low speeds in turn also reduce the performance of the engines.

The object underlying the present invention is therefore to provide a locking segment for a rotor device of a jet engine and a rotor device, by means of which jet engines can be operated at high speeds in the area of a rotor device, while ensuring the required service life.

It is a particular object of the present invention to provide solution to the above problematics by a locking segment having the features of patent Claim 1 and a rotor device having the features of patent Claim 12, respectively.

With a locking segment for axially securing at least one rotor blade on a disk wheel of a rotor device of a jet engine that is operatively connectable to at least one rotor blade and to a disk wheel, it is provided in accordance with the invention that in a first peripheral area of the locking segment that is laterally disposed in the circumferential direction in the installed state, a projecting region is provided, and that in a second lateral peripheral area facing away from the first peripheral area, a receiving region is provided, with the projecting region of the locking segment in the installed state being designed for at least partially overlapping a receiving region of a locking segment that is identical in design and arranged adjacently in the circumferential direction, and for performing frictional work with said receiving region.

Due to the fact that the locking segment in accordance with the invention is, in the installed position, in operative connection with a rotor blade and a disk wheel and is at the same time in frictional engagement with adjacent locking segments, vibrations and oscillations occurring during operation of a rotor device via the locking segment in the area of a rotor blade can be damped in simple manner.

This advantageously offers the possibility of designing rotor blades each with a short blade root having a low mass, said root causing lower stresses in the area of a disk wheel in comparison with known rotor devices during operation of a rotor device even at higher speeds, so that a rotor device or a jet engine designed therewith can be provided that has a required service life or performance.

The vibrations and oscillations of the rotor blades are here damped in that adjacent locking segments move relative to one another in their common overlapping region due to the vibrations and oscillations of the rotor blades interacting therewith, and the frictional force present between the locking segments counteracts the movement of the locking segments and hence of the rotor blades. This is not possible with locking segments known from actual practice, since the considerably smaller end faces of the locking segments do not form any large-area contact surfaces that cause friction.

With a suitable dimensioning of the damping effect of the locking segment in accordance with the invention, there is additionally and advantageously the possibility of dispensing with the damping elements used in known rotor devices in areas between platforms of adjacent rotor blades, leading to elimination of the machining of two long roof-shaped contact surfaces underneath the platform and finally to lower manufacturing costs.

In an advantageous design of the locking segment in accordance with the invention, it is provided that both the projecting region and the receiving region each have at least one contact surface which, in the installed state of the locking segment, interacts with a contact surface of a projecting region or a receiving region of a locking segment adjacently arranged in the circumferential direction, where a normal of the contact surface of the receiving region and a normal of the contact surface of the projecting region are directed in substantially opposite directions. By this measure, a higher frictional force results between two adjacent locking segments and counteracts oscillations or vibrations introduced from the outside, so that good damping of the oscillations and vibrations respectively, is achieved.

In a particularly advantageous development of the invention, the normal of the contact surface of the receiving region and the normal of the contact surface of the projecting region in the installed state point substantially in the axial direction of the disk wheel. By this alignment of the contact surfaces to one another and also to a disk wheel, damping of oscillations and vibrations introduced into the locking segment via rotor blades in an installed state of the locking segment is particularly effective, as it acts mainly on a considerably larger contact surface. In addition to the alignment of the normals of the contact surfaces of the receiving region and of the projecting region of the locking segment pointing exactly in the axial direction relative to a disk wheel in the installed state of the locking segments, the normals can, depending on the respective application, also be designed inclined relative to the axial alignment of the disk wheel or form an acute angle, preferably an angle in the single-digit range.

To permit a large contact area between two adjacent locking segments, the contact surfaces of the projecting region and/or of the receiving region extend, in an advantageous embodiment of a locking segment in accordance with the invention, in the radial direction over an overall width of the locking segment.

There are various possibilities for the design of the contact surfaces. In a simply designed embodiment of the locking segment, both the projecting region and the receiving region are designed as a step with a material thickness reduced in the axial direction in the installed state compared to an area in the middle of the locking segment in the circumferential direction. The shapes of the steps in the projecting region and in the receiving region are designed correlating to one another such that in the installed state they interact in a simple way that is favourable in terms of installation space.

A material thickness of the locking segments can, starting from the steps of the projecting region and of the receiving region, increase in particular in linear manner in a direction facing away from the contact surfaces, so that the material thickness of the locking segment decreases in particular in linear manner in the direction of the steps, starting from a material thickness applying in a middle area of the locking segments and adapted to a width of the grooves of the disk wheel and of the rotor blades.

A locking segment in accordance with the invention withstands stresses in an installed state particularly reliably when a material thickness of the projecting region and of the receiving region in the axial direction is at least approximately half of a material thickness of the locking segment in an area which is in the middle in the circumferential direction, so that a stress arising in the overlapping region in the installed state of the locking segment can be evenly distributed to the respective adjacent locking segments.

The total of a wall thickness of the projecting region and of a wall thickness of the receiving region is in particular equal to a wall thickness in a middle area of the locking segment, so that the locking segments can be installed securely into the grooves of the rotor blades and of the disk wheel.

In an advantageous embodiment of the locking segment, both the projecting region and the receiving region have a material thickness which is at least approximately comparable to a material thickness of an area of the locking segment which is in the middle in the circumferential direction. The material thickness here substantially corresponds to half of a width of the grooves of a disk wheel or of rotor blades intended to receive the locking segments. The locking segment is, in this embodiment in particular, designed using a material having a good bending resistance.

Two locking segments adjacent in the installed state can each be designed curved in the axial direction in an area adjoining the overlapping region. Alternatively, two locking segments adjacent in the circumferential direction in the installed state can be offset overall to one another in the axial direction, while interacting in the overlapping region.

To ensure that the locking segment in an installed state can readily absorb oscillations from the rotor device, it is provided in a development of the invention that a contour facing outwards in the radial direction in the installed state of the locking segment has at least one contact area for making contact with at least one rotor blade, said contact area extending in the circumferential direction substantially only over part of the length of the locking segment. The contour is here in particular designed such that in the installed state of the locking segment it interacts only with at least one area of the rotor blade which during operation receives oscillation movements with particular sensitivity.

In an advantageous development of a locking segment in accordance with the invention, it is provided that the locking segment contour facing at least one rotor blade in the installed state of the locking segment has at least two contact areas which interact in particular with different rotor blades in the installed state of the locking segment.

Furthermore, a rotor device for a jet engine with a disk wheel and several rotor blades connected to said disk wheel is proposed, the rotor blades being arranged in each case via a blade root substantially in the axial direction inside recesses of the disk wheel. Several locking segments according to the present invention are provided for axially securing the rotor blades in the recesses of the disk wheel, said locking segments interacting on the one hand with grooves of the rotor blades and on the other hand with at least one groove of the disk wheel, where a projecting region of a locking segment overlaps with a receiving region of a locking segment adjacent in the circumferential direction in order to perform frictional work during operation of the rotor device.

The rotor device in accordance with the invention designed with locking segments in accordance with the invention can, in the area of the rotor blades and also in areas of the disk wheel receiving the blade roots, advantageously have smaller dimensions due to the lower stresses even at higher speeds, and hence be designed with a lower dead weight and also manufactured less expensively, without detriment to the service life of known rotor devices, or with a longer service life or better operating performance in comparison with known rotor devices.

In an advantageous embodiment of a rotor device in accordance with the invention, locking segments are provided for securing the rotor blades in the axial direction on both sides of the rotor blades. If a plurality of and in particular all locking segments are designed with a projecting region and a receiving region and if these overlap with respectively adjacent locking segments in the circumferential direction, a particularly high damping effect of oscillations and vibrations respectively, of the rotor blades occurring during operation can be achieved by the locking segments. Alternatively, locking segments can be arranged exclusively on a front or on a rear side of the rotor blades.

In order to further increase a damping effect of a rotor device in accordance with the invention, a damping device can be provided in an area between platforms of adjacent rotor blades on a side of the platforms facing in the direction of a rotary axis of the rotor device.

Both the locking segment in accordance with the invention and the rotor device in accordance with the invention can be used for a variety of engine designs and are applied in particular for any required stages of turbines. Furthermore, the locking segment in accordance with the invention, and the rotor device in accordance with the invention can for example also be used in a compressor or a fan of an engine.

Both the features stated in the patent Claims and the features stated in the following exemplary embodiment of the locking segment in accordance with the invention and of the rotor device in accordance with the invention are each suitable, singly or in any combination with one another, to develop the subject matter of the invention. The respective feature combinations do not represent any restriction with regard to the development of the subject matter in accordance with the invention, but have substantially only an exemplary character.

Further advantages and advantageous embodiments of a locking segment in accordance with the invention and of a rotor device in accordance with the invention become apparent from the patent Claims and the exemplary embodiment described in principle in the following with reference to the accompanying drawing. In the drawing,

FIG. 1 shows a highly schematized longitudinal sectional view of a jet engine featuring a turbine provided with several rotor devices,

FIG. 2 shows a schematized detail of the sectional view of FIG. 1, illustrating more clearly two stages of the rotor device, each having rotor blades secured by locking segments in the axial direction inside a disk wheel,

FIG. 3 shows a simplified view of three locking segments of a rotor device of FIG. 2 in stand-alone position, with the locking segments being designed in accordance with the present invention and arranged adjacently in the circumferential direction,

FIG. 4 shows a simplified representation of a detail of the locking segments of FIG. 3, illustrating an overlapping region of two adjacent locking segments,

FIG. 5 shows simplified sectional representations of details of locking segments, each corresponding to FIG. 4, the locking segments being differently designed in the area of the overlapping region, and

FIG. 6 shows a simplified cross-sectional view of a rotor device of FIG. 2 with a damper underneath the platform.

FIG. 1 shows a jet engine 1 in a longitudinal sectional view, with the jet engine 1 being designed with a bypass duct 2 and an intake area 3. A fan 4 adjoins the intake area 3 on the downstream side in a manner known per se. Again downstream of the fan 4, the fluid flow in the jet engine 1 splits into a bypass flow and a core flow, with the bypass flow flowing through the bypass duct 2 and the core flow into an engine core 5 which is in turn designed in a manner known per se with a compressor device 6, a burner 7 and a turbine device 8.

The turbine device 8 has in this case three rotor devices 9, 10, 11 designed in a substantially comparable manner, where the rotor device 9 and the rotor device 10 are illustrated in more detail in FIG. 2.

The rotor device 9 representing a first stage of the turbine device 8 is designed with a centrally arranged disk wheel 13 connected to an engine axis 12, on which a plurality of rotor blades 14 is arranged in radially outer areas on the circumferential side. The rotor blades 14 each have a blade root 15 designed as a fir-tree root and shown here only in schematic form, via which the rotor blades 14 are arranged in a manner known per se inside recesses 16 of the disk wheel 13 which run substantially in the axial direction in the disk wheel 13 and correlate with the fir-tree roots 15.

For axially securing the rotor blades 14 relative to the disk wheel 13, a locking ring 18, 19 with several locking segments 17 is provided on a side of the rotor device 9 facing a flow in a jet engine turbine and on a side of the rotor device 9 facing away from the flow in the jet engine 1 respectively, or on both sides of the rotor blades 14 of the rotor device 9. The locking rings 18, 19 are of substantially identical design, where the front locking ring 18 arranged on that side of the rotor blades 14 facing the intake area 3 is described in the following representatively for the rear locking ring 19 arranged on that side of the rotor blades 14 facing away from the intake area 3.

The front locking ring 18 engages with its locking segments 17 in the area of the fir-tree roots 15 of the rotor blades 14 on the one hand in a groove 20 provided continuously in the disk wheel 13 and on the other hand in grooves 22 of the rotor blades 14 arranged underneath platforms 21 or an inner shroud of the rotor blades 14 and extending in the circumferential direction of the disk wheel. At the same time the rear locking ring 19 engages with its locking segments 17 in the area of the fir-tree roots 15 of the rotor blades 14 on the one hand in a groove 20A provided continuously in the disk wheel 13 and on the other hand in grooves 22A of the rotor blades 14 arranged underneath platforms 21 of the rotor blades 14 and extending in the circumferential direction of the disk wheel.

FIG. 3 shows three locking segments 17A to 17C, adjacent in the circumferential direction, of the front locking ring 18, which are all identical in design.

The locking segments 17A to 17C made using a metallic material have on their side facing the grooves 22 of the rotor blades 14 in the installed state not a concentric surface, but a contour 23 with, in the present case, three contact areas 24, 25, 26, which have a larger radial extent than the areas between the contact areas 24, 25, 26. Between each two contact areas 24, 25 and 25, 26 respectively, a radial extent of the locking segments 17A to 17C is reduced in the form of a rounded part.

The locking segments 17A to 17C each extend in the installed state over several rotor blades 14, in the present case three, where in each case one contact area 24, 25, 26 or several contact areas 24, 25, 26 of the locking segments 17A to 17C interact(s) with a rotor blade 14.

The contact areas 24, 25, 26 of the locking segments 17A to 17C are arranged here relative to the rotor blades 14 such that they each interact with areas of the rotor blades 14, in which in each case a curve, varying in the circumferential direction of the rotor blades 14, of an oscillation amplitude of the displacement components of the oscillations of the rotor blades 14 occurring in all directions during operation of the jet engine 1 is at least approximately at its maximum underneath the platform 21. The oscillations of the rotor blades 14 are then transmitted to a required extent to the locking segments 17A to 17C when the contact areas 24, 25, 26 are each arranged directly underneath those areas of the rotor blades 14 in which the maximum of the oscillation movements is underneath the platform 21.

Contact areas between the adjacently arranged locking segments 17A to 17C are shown highly simplified in FIG. 3, with the contact area between the locking segments 17A and 17B being shown in more detail in FIG. 4.

A first peripheral area, laterally disposed in the circumferential direction, of the locking segment 17A shown in FIG. 4 is designed as a receiving region 27. In the case of the locking segment 17B of identical design and arranged adjacently thereto, a lateral peripheral area 28 facing the first peripheral area 27 is a projecting region. The projecting region 28 of the locking segment 17B encompasses the receiving region 27 of the locking segment 17A in the installed state of the locking segments 17A and 17B, with the receiving region 27 and the projecting region 28 forming an overlapping region 29. In the overlapping region 29, the peripheral areas 27 and 28 of the locking segments 17A and 17B are arranged at least partially one behind the other in the axial direction. The projecting region 28 can be arranged in the axial direction either in front of or behind the receiving region 27.

The receiving region 27 of the left-hand locking segment 17A has a contact surface 30 which in the installed state of the locking segments 17A, 17B interacts with a contact surface 31 of the right-hand locking segment 17B. The contact surfaces 30, 31 are arranged substantially parallel to one another, where normals point to the contact surfaces 30, 31 in directions opposite to one another. The normals to the contact surfaces 30, 31 face substantially in the axial direction, but can also be inclined relative to this direction in particular about an axis pointing in the radial direction and/or an axis pointing in the circumferential direction.

Both the contact surface 30 of the receiving region 27 and the contact surface 31 of the projecting region 28 are arranged in the area of a step 32, 33 of the respective locking segment 17A or 17B, which each have in the axial direction about half of a material thickness of the locking segment 17 otherwise designed with a constant material thickness.

An end face 34 of the step 32 of the receiving region 27 of the left-hand locking segment 17A forms a stop for a shoulder 35 of the step 33 of the projecting region 28 of the right-hand locking segment 17B.

Both the receiving region 27 of the locking segment 17A and the projecting region 28 of the locking segment 17B extend in the radial direction over the entire locking segment 17A and 17B respectively, where an end face 36 of the step 33 of the projecting region 28 is in the present case curved in the radial direction and is designed least approximately semi-circular.

FIG. 5 a shows a section through the two locking segments 17A and 17B shown in FIG. 4 and arranged adjacently to one another in the installed state.

FIG. 5 b shows two alternatively designed locking segments 17D, 17E in which a material thickness decreases, in the present case in linear manner, starting from a thickness adapted to a groove width of the rotor blades 14 and of the disk wheel 13, in the direction of the steps 32, 33 with the contact surfaces 30, 31, to a thickness which corresponds to around half the maximum material thickness of the locking segments 17D, 17E.

A further alternative embodiment of the locking segments 17F, 17G is shown in FIG. 5 c. The locking segments 17F, 17G have overall a thickness substantially corresponding to half a groove width of the rotor blades 14 or of the disk wheel 13, where the locking segments 17F, 17G adjacent in the circumferential direction in the installed state together have in the overlapping region 29 a thickness corresponding to the groove width. In an area adjoining the overlapping region 29, the locking segments 17F, 17G are each designed curved in the axial direction.

The locking ring 18 is installed substantially as in known solutions, with the locking ring 18 having pre-curved part sections to provide an annular closure for the entire rotor blade set in the known manner. The locking segments 17 are inserted one after the other into the grooves 20, 22 of the rotor blades 14 and of the disk wheel 13 in the circumferential direction, with adjacent locking segments 17 each interacting via a receiving region 27 and a projecting region 28. In the circumferential direction, the contact areas 24, 25, 26 are placed with the rotor blades 14 at required positions underneath the blade platform 21. A locking plate known from actual practice is used to secure the position of the locking segments 17 in the circumferential direction.

A locking ring 38 designed comparable to the locking rings 18, 19 with locking segments 43 designed substantially identical to the previously described locking segments 17 or 17A to 17G is provided for axial securing of rotor blades 37 in a disk wheel 39 of the rotor device 10 designed comparable to the rotor device 9 and representing a second stage of the turbine device 8. The rotor blades 37 are secured against a movement of the rotor blades 37 in the axial direction relative to the disk wheel 39 by the locking ring 38 arranged on a side of the rotor blades 37 facing away from the intake area 3 on the one hand and by a stop arranged on the other side of the rotor blades 37 on the other hand.

The design described above of the locking segments 17 and 43 respectively, is used during operation of the jet engine 1 to damp oscillations and/or vibrations of the rotor blades 14, 37 occurring in particular in the radial direction, which are in particular incited thereto by stator vanes arranged upstream of the rotor blades 14, 37. The radial components of maximum oscillation movements occurring during operation of the rotor blades 14, 37 underneath the platform 21 are here received by the contact areas 24, 25, 26 of the locking segments 17, 43 and transmitted via the contact surfaces 30, 31 between the locking segments 17, 43.

Since the locking segments 17 and 43 respectively, interact with different rotor blades 14, 37, position differences and time lags of the oscillations of the rotor blades 14, 37 cause relative movements of the locking segments 17 and 43 respectively, to one another. These relative movements of the locking segments 17 and 43 respectively, to one another result in a movement of the receiving regions 27 of locking segments 17 and 43 respectively, relative to the projecting regions 28 of adjacent locking segments 17 and 43 respectively. Frictional work in the form of metal abrasion between the locking segments 17 and 43 respectively, is performed via the contact surfaces 30, 31 of the respective receiving regions 27 and projecting regions 28, with the locking segments 17, 43, as a result converting the kinetic energy of the blade oscillations by friction and generated heat and/or by metal wear on the contact surface 30, 31 into deformation energy. This energy conversion by the locking segments 17, 43 counteracts the oscillations and vibrations of the rotor blades 14, 37, such that the latter are damped.

To increase damping of the oscillations of the rotor blades 14, 37 additionally to the damping effect of the locking rings 18, 19, 38 with the locking segments 17 and 43 respectively, additional damping devices 41 are provided in the view, in a highly schematized representation in FIG. 6, of a cross-section through the rotor device 9 of the jet engine 1, and have damping elements substantially known per se, but which can if necessary be dimensioned smaller. The damping devices 41 are located in intermediate spaces 40 arranged between the fir-tree roots 15 of the rotor blades 14 and the platforms 21 in the area of blade necks 42, or in intermediate spaces 40 confined by the latter.

The locking segments 17, 43 in accordance with the invention can however also have a damping effect against blade and disk oscillations so great that damping devices 41 can be dispensed with.

LIST OF REFERENCE NUMERALS

-   1 Jet engine -   2 Bypass duct -   3 Intake area -   4 Fan -   5 Engine core -   6 Compressor device -   7 Burner -   8 Turbine device -   9, 10, 11 Rotor device -   12 Engine axis -   13 Disk wheel -   14 Rotor blade -   15 Fir-tree root -   16 Recess -   17 Locking segment -   17A-17G Locking segment -   18, 19 Locking ring -   20, 20A Groove of disk wheel -   21 Platform of rotor blade -   22, 22A Groove of rotor blade -   23 Radial outer contour of locking segment -   24, 25, 26 Contact area -   27 Receiving region of locking segment -   28 Projecting region of locking segment -   29 Overlapping region -   30 Contact surface of receiving region -   31 Contact surface of projecting region -   32 Step of receiving region -   33 Step of projecting region -   34 End face of step of receiving region -   35 Shoulder of projecting region -   36 End face of step of projecting region -   37 Rotor blade -   38 Locking ring -   39 Disk wheel -   40 Intermediate space -   41 Damping device -   42 Blade neck -   43 Locking segment 

1. A retaining segment for axially securing at least one rotor blade on a disk wheel of a rotor device of a jet engine that is operatively connectable to at least one rotor blade and to a disk wheel, wherein a first peripheral area of the retaining segment that is laterally disposed in the circumferential direction in the installed state, a projecting region is provided, and that in a second lateral peripheral area facing away from the first peripheral area, a receiving region is provided, with the projecting region of the retaining segment in the installed state being designed for at least partially overlapping a receiving region of a retaining segment that is identical in design and arranged adjacently in the circumferential direction, and for performing frictional work with said receiving region.
 2. The retaining segment in accordance with claim 1, wherein both the projecting region and the receiving region of the retaining segment each have at least one contact surface which, in the installed state of the retaining segment, is designed for interacting with a contact surface of a projecting region or a receiving region of a retaining segment arranged adjacently in the circumferential direction, where a normal of the contact surface of the receiving region and a normal of the contact surface of the projecting region are directed in substantially opposite directions.
 3. The retaining segment in accordance with claim 2, wherein the normals of the contact surface of the receiving region and of the contact surface of the projecting region in the installed state point substantially in the axial direction.
 4. The retaining segment in accordance with claim 2, wherein the contact surfaces of the projecting region and/or of the receiving region extend in the radial direction over an overall width of the retaining segment.
 5. The retaining segment in accordance with claim 1, wherein both the projecting region and the receiving region are designed as a step with a material thickness reduced in the axial direction in the installed state compared to an area in the middle of the retaining segment in the circumferential direction.
 6. The retaining segment in accordance with claim 5, wherein a material thickness of the projecting region and of the receiving region in the axial direction is at least approximately half of a material thickness of the retaining segment in an area which is in the middle in the circumferential direction.
 7. The retaining segment in accordance with claim 5, wherein an end face of the step of the receiving region forms a stop and the step of the projecting region has a shoulder, with the end face of the step of the receiving region in the installed state of the retaining segment being designed for interacting with a shoulder of a retaining segment arranged adjacently in the circumferential direction.
 8. The retaining segment in accordance with claim 1, wherein both the projecting region and the receiving region have a material thickness which is at least approximately comparable to a material thickness of an area of the retaining segment which is in the middle in the circumferential direction.
 9. The retaining segment in accordance with claim 8, wherein two retaining segments adjacently arranged in the installed state are each designed curved in the axial direction in an area adjoining the overlapping region.
 10. The retaining segment in accordance with claim 1, wherein a contour facing outwards in the radial direction in the installed state of the retaining segment has at least one contact area for making contact with at least one rotor blade, said contact area extending in the circumferential direction substantially only over part of the length of the retaining segment.
 11. The retaining segment in accordance with claim 10, wherein the retaining segment contour facing at least one rotor blade in the installed state of the retaining segment has at least two contact areas which interact in particular with different rotor blades in the installed state of the retaining segment.
 12. A rotor device for a jet engine with a disk wheel and several rotor blades connected to said disk wheel, with the rotor blades being arranged in each case via a blade root substantially in the axial direction inside recesses of the disk wheel, with several retaining segments according to claim 1 being provided for axially securing the rotor blades in the recesses of the disk wheel, said retaining segments interacting on the one hand with grooves of the rotor blades and on the other hand with at least one groove of the disk wheel, and with at least one projecting region of a retaining segment overlapping a receiving region of a retaining segment adjacently arranged in the circumferential direction in order to perform frictional work during operation of the rotor device.
 13. The rotor device in accordance with claim 12, wherein retaining segments are provided in the axial direction on both sides of the rotor blades.
 14. The rotor device in accordance with claim 12 wherein a damping device is provided in an area between platforms of adjacent rotor blades on a side of the platforms facing in the direction of a rotary axis of the rotor device. 